[0001]
The present invention relates to a polishing art, particularly to a CMP (chemical mechanical polishing) art and for example, an art which is effective in using for chemically and mechanically polishing the patterned surface of a patterned semiconductor wafer (hereafter referred to as a wafer).
[0002]
Recently, a method for manufacturing a semiconductor apparatus for flattening concave and convex parts of the patterned surface of a patterned wafer by the chemical mechanical polishing method has been proposed. The art for flattening concave and convex parts of the patterned surface of a patterned wafer by the chemical mechanical polishing method polishes the patterned wafer by rubbing it against a polishing tool, so that the concave and convex parts of the patterned surface of the wafer can be flattened promptly and precisely.
[0003]
The chemical mechanical polishing machine executing the chemical mechanical polishing method used for flattening includes a polishing tool pasted on the rotary table formed in a disk shape, a head rotating on its axis in the state of holding a patterned wafer, and a slurry supplier for supplying a polishing lubricant which is called slurry in which fine abrasives are suspended in pure water to the polishing tool and is structured so as to drop slurry on the polishing surface of the polishing tool and then perform chemical mechanical polishing by pressing the polished surface of the patterned wafer held by the head rotating on its axis against the polishing surface of the rotating polishing tool.
[0004]
However, in the chemical mechanical polishing method, there are many foreign substances on the polishing surface of a polishing tool such as clustered particles of abrasives included in the slurry, broken pieces caused by a wafer crushed during polishing, and dust, and these foreign substances cannot be fully removed from the polishing surface only by rinsing slurry and remain on the polishing surface. The polished surface of the patterned wafer is damaged by foreign substances remaining on the polishing surface and hence the base pattern is damaged, so that reliable chemical mechanical polishing cannot be executed stably.
[0005]
As a means for solving this problem of the chemical mechanical polishing method, the following polishing machine is proposed in Japanese Patent Application Laid-Open 8-294861. Namely, the polishing machine has a liquid drain mechanism for removing polishing waste liquid from the polishing surface during polishing backward in the rotational direction in the patterned wafer rubbing area of the polishing tool and is structured so as to forcibly drain slurry waste liquid used for polishing once by the liquid drain mechanism.
[0006]
However, it is made clear by the inventor of the present invention that in the aforementioned polishing machine, particles with comparatively large diameters such as several .mu.m or more and particles caused by chipping of a grindstone generated when a fixed abrasive is used as a polishing tool instead of polishing cloth cannot be removed fully, so that there is a problem imposed that reliable chemical mechanical polishing cannot be executed stably. The polishing art using the aforementioned fixed abrasive is disclosed in International Patent Publication WO97/10613.
[0007]
As slurry, fine abrasives with diameters from several tens .mu.m to sub .mu.m such as silicon oxide and cerium oxide are used, so that slurry is a very expensive material. On the other hand, slurry is rinsed, so that almost all slurry is drained without contributing to chemical mechanical polishing. Therefore, when very expensive slurry is rinsed and forcibly drained without contributing to polishing, not only the running cost of the polishing machine will increase and the cost of the flattening step of patterned wafers but also the cost of the whole manufacturing method of a semiconductor apparatus will increase.